Anaesthetic supply

ABSTRACT

The specification discloses the combination of a bottle and a connecting cap therefor, both components having mating screw threads, the components having a mating key and keyway system extending axially of the bottle neck and being designed so that mating of the key and keyway system is necessary before relative rotation between the cap and the bottle to screw the cap onto the bottle is possible. Thus, a connecting cap can only be secured to a bottle if the bottle and cap are complementary and the potential danger of connecting a bottle containing the wrong liquid to, for example, an anaesthetic vapouriser, can be avoided.

United States Patent [191 Jones Dec. 18, 1973 [5 ANAESTHETIC SUPPLY 3,693,820 9/1972 Linkletter 215/9 75 l e t Wilfr d ne Kehl ,*E l d 1 m n or e Jo lg ey ng an Primary Examiner-George T. Hall Assigneez yp n Limited, g y, Attorney-Richard K. Stevens et al.

Yorkshire, England [22] Filed: May 10, 1972 ABSTRACT [30] Foreign Application Priority Data May [0, l97l Great Britain [4,023/7l [52] US. Cl 215/44, 215/9, 215/73 [51] Int. Cl 865d 55/02 [58] Field of Search 215/44, 43, 73, 9

[56] References Cited UNITED STATES PATENTS 3,684,l l7 8/1972 Leopoldi 215/9 The specification discloses the combination of a bottle and a connecting cap therefor, both components having mating screw threads, the components having a mating keyand keyway system extending axially of the bottle neck and being designed so that mating of the key and keyway system is necessary before relative rotation between the cap and the bottle to screw the cap onto the bottle is possible. Thus, a connecting cap can only be secured to a bottle if the bottle and cap are complementary and the potential danger of connecting a bottle containing the wrong liquid to, for example, an anaesthetic vapouriser, can be avoided.

13 Claims, 9 Drawing Figures PAIENIE m1 81973 SHEET 10F 2 PATENIEH DEC 1 8 I975 SHEET 2 BF 2 ANAESTHETIC SUPPLY This invention relates to a safety system for the supply of liquid anaesthetics from bottles.

Our British Pat. No. 1,193,241 describes and claims a filling system for use with volatile liquid anaesthetic vapourising apparatus designed to ensure that only a connector of a certain form can be connected to the apparatus to fill this with anaesthetic and drain anaesthetic therefrom. The connector is secured to one of a tube having a bottle cap at the other end for screwing on to a bottle of liquid anaesthetic. Some anaesthetic bottles have different designs of neck and cap according to the anaesthetic contained therein; and thus by providing a tube with a specific form of cap at one end and a specific form of connector at the other end, vapourising apparatus designed for a particular anaesthetic may only be connected to a bottle containing that anaesthetic. This system works well, but there is a limit to the possible variations'of bottle neck based on differences of diameter or screw thread parameters.

According to the present invention we provide the combination of a bottle and a connecting cap therefor, both components having mating screw threads, the components having a mating key and keyway system extending axially of the bottle neck and being designed so that mating of the key and keyway system is necessary before relative rotation between the cap and the bottle to screw the cap onto the bottle is possible.

Thus, the invention does not rely merely on different threads, but rather on a key and keyway system, fixing of the cap to the bottle only being possible if both key and keyway systems and threads engage. It will be evident that many different forms of keys and keyways can be provided by varying the number of keys and keyways, their sizes and their angular spacing, and all these forms may be used with one standard thread formation. If the number of possible combinations is not sufficient, then a similar range may be provided with a different thread, so that even if the wrong cap having engaging keys and keyways was selected the threads would not mate and the cap could not be screwed to the bottle.

The invention also includes the individual bottles and bottle caps for use in a combination as aforesaid, and a bottle for use in the combination comprises a neck of substantially circular crosssection and having screw threads extending around the neck, and one element of a key and keyway system formed on the neck or on a member axially secured to the neck, the element extending axially of the neck.

A bottle cap for use in the combination is formed with circumferentially extending screw threads, and one element of a key and keyway system extending axially of the cap.

Although the elements of the key and keyway system must have a directional component extending axially of the bottle neck it is not essential that these elements extend exactly parallel to the axis of the neck, although this is preferred. Thus, it would be possible to provide key and keyway elements inclined to the bottle axis so that some rotation of the cap on the bottle to engage fully the key and keyway elements would be necessary. Such rotation would be entirely independent of any rotation to screw the cap onto the bottle, and may in the same or the opposite sense to the rotation needed for screwing the cap onto the bottle.

There are a number of ways in which the mating key and keyway system may be provided. The first of these is to interrupt the thread on the neck of the bottle with at least two axially extending keyway grooves and to provide the matching cap with at least two key ribs which may pass down the keyways and beyond the thread on the bottle before the threads on the cap engage the threads on the bottle. After the keyways have engaged properly and the threads mate then the cap may be screwed on to the bottle. The second possibility is to form the upper end of the internal bore of the neck of the bottle with a reduced diameter portion in which are formed at least two axial grooves forming keyways opening into the larger diameter portion below the reduced diameter portion. The cap for the bottle is then provided with centre spigot having appropriate ribs forming keys on its radially outer surface which keys may pass down through the keyways into the larger diameter part of the neck whereupon the cap will be free to rotate so that the threads on the cap and the bottle may engage. In the inverse of this system the internal bore of the neck of the bottle has axially extending ribs forming keys projecting radially inwardly and the centre spigot of the cap is of a diameter such that it may fit between the keys. The lower end of the spigot is provided with an enlarged diameter head having keyways cut in it to mate with the keys. Thus, only when the head has passed below the keys can the cap be rotated to engage the screw threads.

These three methods will all give the desired result but they have the common disadvantage that they require special individual bottle moulds for each of the various anaesthetics. Manufacture of all these individual bottles in relatively small quantities is not particularly economic and could lead to unacceptably high costs.

The most desirable form of system is one in which the bottle manufacturers can make a perfectly standard bottle which can then be easily adapted to suit the safety system contemplated by the invention.

Preferably therefore, a bottle for use in the safety system has a neck which is formed with an annular ridge on the outer surface thereof between the screw threads and the body of the bottle and the element of the key and keyway system is formed by or on a collar fitting around the neck and held axially thereon by the annular ridge. A cap for use with this bottle is formed with two axial sections, the first of which is formed with screw threads and a second of which forms or carries an element of the key and keyway system.

The arrangement must be such that unless the keys and keyways on the ring and the sleeve engage then the threaded member of the cap is held axially above the threads on the neck of the bottle. Only when the keys and keyways have engaged can the cap descend sufficiently far for the threads to engage.

A number of embodiments of bottles and caps according to the invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 shows a cross section through a first embodiment of bottle and cap according to the invention;

FIG. 2 is an underneath plan view of a collar on the bottle of FIG. 1;

FIG. 3 is an underneath plan view of the cap shown in FIG. 1;

FIG. 4 is an underneath plan view of an alternative form of collar;

FIG. is a cross-section through part of a cap for use with the collar shown in FIG. 4;

FIG. 6 is an underneath plan view of a third embodiment of collar;

FIG. 7 is a cross-section taken through one half of an alternative bottle and cap formation according to the invention; and

FIGS. 8 and 9 show two further embodiments of bottles and caps according to the invention.

Referring to FIG. 1 this shows a standard bottle 1 having a neck formed with a conventional screw thread 2 on the outer surface thereof and having below the thread an annular ridge 3. Fitted over the ridge is a collar 4 which is conveniently a plastics moulding. The collar is formed with a number of radially inwardly projecting flexible fingers 5 which may be sprung over the annular ridge 3 to secure the collar axially in position on the neck of the bottle. The collar has a flange 6 which engages the ridge 3 on the opposite side to the fingers 5. The radially outer surface of the collar is provided with two axially extending ribs 7 and 8 forming key elements. As an alternative to the fingers 5 the collar may have a radially inwardly projecting continuous flexible flange which may deform and engage behind the ridge 3.

The cap for use with this bottle comprises first and second axial sections 9 and 10 respectively, the first section having an internal thread 11 and having a knurled outer surface 12. Secured to this section is a tube 13 carrying at its other end the connector for the vapourising apparatus, the tube opening into the cap and the opening being suitably sealed. The second section of the cap is in the form of an annular sleeve and is provided with two axially extending grooves 14 and 15 forming keyway elements.

In use the cap must be aligned so that key 7 engages keyway l4 and key 8 engages keyway 15, whereupon the cap is allowed to move onto the bottle to a position wherein the threads 2 and 11 may be placed in mating engagement. The cap is then screwed onto the bottle neck, the collar 4 rotating on the neck as screwing of the cap takes place.

It will be seen that this arrangement enables a completely standard bottle to be made. The collar 4 can be fitted before the bottle is filled or after filling and before or after the normal bottle cap is fitted. This system may be brought into use at any stage right down from the bottle manufacturers to the individual hospitals to whom the drugs are supplied. For rapid identification it may be advantageous to colour the collars 4 and the corresponding caps so that it is only necessary to select the two items of the same colour to ensure that they will be a mating set. Both collars and caps may also, if desired, be engraved or otherwise marked with the name of the drug concerned.

It will be evident that the number of keys provided on the collar 4 is not critical although two may be found to be the preferred number. To provide a number of different key arrangements it is only necessary to change the angle a in FIG. 3) between the centre lines of the keys l4 and 15. The ribs forming the keys may have a cross-section of any desired shape, and may for example be round or square or formed to any other more complex section.

FIGS. 4 and 5 show an alternative embodiment of collar and cap which may be used in combination with a bottle in the same way as described with reference to FIG. I. In this arrangement the collar again has resil- 5 ient fingers 21 for fitting over the ridge on the neck of the bottle but in this case the radially outer surface of the collar is formed with axially extending grooves 22 and 23 forming keyways. The cap 24 for use with this collar is again in two axial sections 25 and 26, the second section being in the form of an annular sleeve formed on its radially inner surface with two axially extending ribs 27 and 28. The angular disposition of the ribs 27 and 28 is the same as that of the grooves 22 and 23 so that the cap can be mated with the collar and moved to a position on the bottle wherein the screw threads 29 on the first section of the cap can engage the threaded neck of the bottle. Once again the number, disposition and form of the keys and keyways may be varied as desired.

FIG. 6 shows a further alternative form of collar that may be applied to a bottle as shown in FIG. 1. In this case the collar 30 has a radially inner surface 31 of substantially annular form, and is formed with a number of resilient fingers such as 32 for fitting over the ridge on the bottle neck. The radially outer surface of the collar is hexagonal and in itself forms a key element. A cap for use with this collar will be of similar form to that shown in FIG. 5, but the skirt 26 of the cap will be hexagonal to fit over the hexagonal collar. It will be understood that collars have polygonal outer surfaces with sides numbering other than six may also be used, in conjunction with caps having mating polygonal skirts. Such cap and bottle combination are used in exactly the same way as described with reference to FIG. 1.

FIG. 7 shows part of the neck of a standard bottle having a conventional screw thread 41 on the outer surface thereof and having below the thread an annular ridge 42. Fitted over the ridge is a collar 43 which may conveniently be a zinc base die casting having four fingers such as 44. Before fitting, the fingers 44 will lie in the same plane as the rest of the ring so that the ring may be passed over the thread and on to the ridge and the fingers can then be deformed inwardly beneath the ridge to secure the ring to the ridge. The ring has two or more keys 45 formed on the radially outer surface thereof.

The cap for use with this bottle comprises a member 46 having an internal thread 47 and provided with a knurled section 48. Secured to the member 46 is a tube 49 carrying at its other end the connector for the vapourising apparatus, the tube 49 opening into the cap and the opening being suitably sealed. Radially surrounding the member 46 is an annular sleeve 50 made to be axially captive on the sleeve by virtue of the flange surfaces 51 and 52. The lower end of the tubular sleeve is formed with slots or keyways 53 for engaging the keys 45 on the collar 43.

In use the keys and keyways 45 and 53 must be engaged to allow the sleeve 50 to descend to a position wherein the threads 41 and 47 may be placed in mating engagement. The cap is then screwed onto the bottle neck, moving axially within the sleeve and also rotating relative to the sleeve 50 as this occurs. In this arrangement the collar 44 is not capable of rotation relative to the bottle neck as it is in the embodiment described with reference to FIG. 1. It will be understood that the keys and keyways on the collar and the cap may be varied in similar manner to that in which the correspond ing elements shown in FIG. 1 may be varied.

In a modified form the sleeve 50 and part 46 may be made integral, with the sleeve portion having a larger internal diameter than the diameter over the tips of the keys 45 on collar 43. Inside the lower part of the sleeve portion is fitted a ring having an internal diameter greater than the external diameter of collar 43, but less than the diameter over the tops of the keys 45. This ring is interrupted by axial keyways which are designed to mate with the keys. Thus, when the cap is applied the cap and bottle must be in relative angular positions such that the keys pass through the keyways as the cap is lowered on to the bottle. When the keys have passed completely through the keyways the cap is then free to rotate so that it may be screwed on to the bottle.

It will be evident that the system shown in FIG. 7 may be modified by providing the bottle ridge 412 with the appropriate keys or keyways for mating with the keyways or keys of the sleeve 50. However, this would have the disadvantage of requiring separate distinct moulds for bottles destined for each different anaesthetic.

FIGS. 8 and 9 both show further alternative systems which would require separate distinct moulds for bat tles destined for each different anaesthetic. As shown in FIG. 8 the neck of a bottle 60 is formed with an external thread 61 which is interrupted by at least two axially extending grooves such as 62 forming keyway elements. The corresponding cap has a first axial section 63 formed with internal threads 64 and a second axial section 65 in the form of an annular sleeve formed with two axially extending ribs 66 forming keys which may mate with the keyways formed by grooves 62. It will be seen that the cap must be properly aligned with the bottle so that the keys 66 can pass through the grooves 62 before the threaded portions of the cap and the bottle are in engagement.

As shown in FIG. 9 the neck of a bottle 70 has a thread 71 formed externally on the neck, and the internal surface of the neck has a reduced diameter portion 72 extending from the open end of the neck towards the body of the bottle. This portion is formed with two axially extending grooves such as 73 forming keyways opening into a larger diameter portion 74 of the neck. The corresponding cap is formed with a radially outer sleeve 75 on which the screw threads 76 are formed and a radially inner spigot 77 for fitting within the bottle neck. The radially outer surface of that end of the spigot which is axially remote from the screw thread 76 is formed with two axially extending ribs 78 forming key elements which can mate with the keyways formed by the slots such as 73. It will be seen that the keys 78 must be passed through the slot 73 before the screw threads on the cap can engage those on the bottle.

It will be appreciated that the inverse of this last described arrangement may also be used, with axially extending ribs being formed on the inner surface of the bottle neck, and the spigot 77 having an enlarged head formed with axially extending grooves which may mate with the ribs formed on the bottle neck.

The embodiments shown in FIGS. 8 and 9 may of course be modified in the number and formation of the key and keyway elements.

What I claim is:

l. The combination of a bottle and a connecting cap therefor, both components having mating screw threads, the components having a mating key and keyway system extending axially of the bottle neck and being designed so that mating of the key and keyway system is necessary before relative rotation between the cap and the bottle to screw the cap onto the bottle is possible.

2. A combination according to claim ll, wherein said bottle comprises a neck of substantially circular crosssection screw threads extending around said neck, a member axially secured to said neck, and a first element of a key and keyway system formed by or on said member and extending axially of the neck, and said cap is formed with circumferentially extending screw threads, and a second element of said key and keyway system extending axially of said cap.

3. A combination according to claim 2 in which an annular ridge is formed on the outer surface of said neck between said screw threads and the body of the bottle, and said first element is formed by or on a collar fitting around said neck and held axially thereon by said annular ridge, and said cap comprises first and second axial sections, said first section being formed with said screw threads and said second section forming or carrying said second element of said key and keyway system.

4. A combination according to claim 3 in which said collar is of substantially annular form, and said first element is constituted by two or more axially extending ribs forming key elements on the radially outer surface of said collar, and said second axial section of said cap is in the form of an annular sleeve provided with two or more axially extending grooves forming keyway elements.

5. A combination according to claim 3 in which said collar is of substantially annular form and said first element is constituted by two or more axially extending grooves forming keyway elements on the radially outer surface of said collar, and said second axial section of said cap is in the form of an annular sleeve provided with two or more axially extending ribs forming key elements.

6. A combination according to claim 3 in which said collar has a radially inner surface of substantially circular form, and a radially outer surface which is polygonal and in itself forms a key element and said second section of said cap is in the form of a skirt having a polygonal inner surface forming a keyway element.

7. A combination according to claim 3 in which said collar is formed with radially inwardly projecting flexible fingers which may be sprung over said annular ridge to secure the collar axially on said neck.

8. A combination according to claim 3 in which said collar is formed with fingers extending axially from said collar, said fingers being capable of distortion on as sembly to a radially extending position to secure said collar axially on said neck.

9. A combination according to claim 3 in which said collar is rotatable on said neck and said first and second axial sections of said cap form an integral structure.

110. A combination according to claim 8 in which said collar is not rotatable on said neck, and said second section of said cap is axially captive on and rotatable relative to said first section of said cap.

It. A combination according to claim 1 in which said bottle comprises a neck having a screw thread formed thereon, said screw thread being interrupted by at least two axially extending grooves forming keyway elements and said cap comprises first and second axial sections, said first section being formed with screw threads for mating with those on said bottle and said second section being in the form of an annular sleeve provided with two or more axially extending ribs forming key elements.

12. A combination according to claim 1 in which said bottle comprises a neck having a screw thread formed externally thereon and the internal surface of said neck has a reduced diameter portion extending from the open end of the neck towards the body of said bottle, the reduced diameter portion being formed with two or more axially extending grooves forming keyways opening into a larger diameter neck portion, and said cap is formed with a radially outer sleeve on which screw threads for mating with those on said bottle are formed and a radially inner spigot for fitting within said bottle neck, the radially outer surface of that end of the spigot which is axially remote from said screw threads on said cap being formed with two or more axially extending ribs forming key elements.

13. A combination according to claim 1 in which said bottle comprises a neck having a screw thread formed externally thereon and the internal surface of said neck is formed with at least two axially extending ribs forming key elements, and said cap is formed with a radially outer sleeve on which screw threads for mating with those on said bottle are formed and a radially inner spigot for fitting within said bottle neck, the end of said spigot which is axially remote from said screw threads on said cap being formed with an enlarged diameter head having axially extending grooves forming keyway elements. 

1. The combination of a bottle and a connecting cap therefor, both components having mating screw threads, the components having a mating key and keyway system extending axially of the bottle neck and being designed so that mating of the key and keyway system is necessary before relative rotation between the cap and the bottle to screw the cap onto the bottle is possible.
 2. A combination according to claim 1, wherein said bottle comprises a neck of substantially circular cross-section screw threads extending around said neck, a member axially secured to said neck, and a first element of a key and keyway system formed by or on said member and extending axially of the neck, and said cap is formed with circumferentially extending screw threads, and a second element of said key and keyway system extending axially of said cap.
 3. A combination according to claim 2 in which an annular ridge is formed on the outer surface of said neck between said screw threads and the body of the bottle, and said first element is formed by or on a collar fitting around said neck and held axially thereon by said annular ridge, and said cap comprises first and second axial sections, said first section being formed with said screw threads and said second section forming or carrying said second element of said key and keyway system.
 4. A combination according to claim 3 in which said collar is of substantially annular form, and said first element is constituted by two or more axially extending ribs forming key elements on the radially outer surface of said collar, and said second axial section of said cap is in the form of an annular sleeve provided with two or more axially extending grooves forming keyway elements.
 5. A combination according to claim 3 in which said collar is of substantially annular form and said first element is constituted by two or more axially extending grooves forming keyway elements on the radially outer surface oF said collar, and said second axial section of said cap is in the form of an annular sleeve provided with two or more axially extending ribs forming key elements.
 6. A combination according to claim 3 in which said collar has a radially inner surface of substantially circular form, and a radially outer surface which is polygonal and in itself forms a key element and said second section of said cap is in the form of a skirt having a polygonal inner surface forming a keyway element.
 7. A combination according to claim 3 in which said collar is formed with radially inwardly projecting flexible fingers which may be sprung over said annular ridge to secure the collar axially on said neck.
 8. A combination according to claim 3 in which said collar is formed with fingers extending axially from said collar, said fingers being capable of distortion on assembly to a radially extending position to secure said collar axially on said neck.
 9. A combination according to claim 3 in which said collar is rotatable on said neck and said first and second axial sections of said cap form an integral structure.
 10. A combination according to claim 8 in which said collar is not rotatable on said neck, and said second section of said cap is axially captive on and rotatable relative to said first section of said cap.
 11. A combination according to claim 1 in which said bottle comprises a neck having a screw thread formed thereon, said screw thread being interrupted by at least two axially extending grooves forming keyway elements and said cap comprises first and second axial sections, said first section being formed with screw threads for mating with those on said bottle and said second section being in the form of an annular sleeve provided with two or more axially extending ribs forming key elements.
 12. A combination according to claim 1 in which said bottle comprises a neck having a screw thread formed externally thereon and the internal surface of said neck has a reduced diameter portion extending from the open end of the neck towards the body of said bottle, the reduced diameter portion being formed with two or more axially extending grooves forming keyways opening into a larger diameter neck portion, and said cap is formed with a radially outer sleeve on which screw threads for mating with those on said bottle are formed and a radially inner spigot for fitting within said bottle neck, the radially outer surface of that end of the spigot which is axially remote from said screw threads on said cap being formed with two or more axially extending ribs forming key elements.
 13. A combination according to claim 1 in which said bottle comprises a neck having a screw thread formed externally thereon and the internal surface of said neck is formed with at least two axially extending ribs forming key elements, and said cap is formed with a radially outer sleeve on which screw threads for mating with those on said bottle are formed and a radially inner spigot for fitting within said bottle neck, the end of said spigot which is axially remote from said screw threads on said cap being formed with an enlarged diameter head having axially extending grooves forming keyway elements. 